A typical shower stall is generally constructed with three fiberglass walls, a glass door and a shower base. The fiberglass walls are compression molded and are attached together with a tongue and groove mounting system. The molding process puts limitations on the shapes of the walls which can be molded.
Prior tongue and groove mounting systems for shower walls do not allow for a cornerpiece or an angle panel to be compression molded. Compression molding involves two mold halves which are placed together under pressure to mold the desired piece. When the piece is finished, the mold halves must be pulled apart. The shape of the desired piece must allow the mold halves to separate. Prior tongues and grooves prevented the molding of cornerpieces or angle panels because the halves could not be separated after the panel was molded.
In compression molding, use of a mold of more than two pieces is not satisfactory due, at least in part, to the pressure applied during the molding process. A mold of more than two pieces could not be held in place satisfactorily under the pressure and tends to come apart. More over, molds of more than two piece construction at their best are complicated and expensive. The inability satisfactorily to mold corner panels has put severe limitations on the shape and style of shower stalls that could be completely molded.